Figure 5. HCMV triggers cell proliferation via IL-6-STAT3 activation in HepG2 cells and PHH.

HepG2 cells (6×10⁶ cells) and PHH (2×10⁶ cells) were left uninfected or infected with AD169 (MOI = 0.5) and UV-inactivated HCMV. Cell proliferation was measured by monitoring the expression of Ki-67 Ag using flow cytometry and MTT assay as described in the Materials and Methods. (A) Ki67 Ag expression as measured by flow cytometry. MFI, mean fluorescence intensity. Results are representative of two independent experiments. (B) Histograms show Ki-67 Ag and MTT data from two independent experiments. (C) Increased cell proliferation in HepG2 cells infected with AD169 is blocked by a neutralizing anti-IL-6R mAb (10 microg/ml), a Jak inhibitor (1 micromol/l) and a STAT3 inhibitor (10 micromol/l), and decreased cell proliferation was observed in HepG2 cells infected with UV-inactivated HCMV. Mean values ± SD are representative of two independent experiments.